chicksmom

my husband just purchased a 1981 chevy corvette and have been having problems with rough idleing and rpm's going up and down. he noticed air getting in around the gasket to the carburetor and we replaced it today. so he took it for a test run and it is leaking fuel from a black canister on the drivers side under the wheel well near the bottom of the car. He cant find out any information on what this part is. Any one have any idea's? I have gotten very good information on this site and I just know there is someone out there that can help us! thanks alot in advance for any help.

72rdstr

Sounds like the vapor canister. Supposed to capture gas FUMES and route them back to the tank.
Anyone know if the carb float is set too high (or needle is stuck open) will cause this?

chicksmom

fairly new to all of this, how do I tell if the carb float it set right? or if the needle is stuck open? also would this cause the rpm's to go up and down,and the choke light to come on? thanks so much for your help so far.

Paul Borowski

It is NOT "visible" to check. The float has probably developed a hole, filled with fuel, sunk and is leaving the needle valve off of the seat letting a flow of fuel continue until it fills the carb, then down and over to your canister. Most likely your carb needs disassembled and a new float, needle & seat & gasket set installed.

72rdstr

Yes. I think Lars is the local carb guru but this is something a simple rebuild should fix. Most better kits have a small measuing device made out of paper that can help you set the float level. If it is one of the newer plastic type floats, they'll sometimes become saturated and sink.

Rockn-Roll

Yeah, the black cannister is a vapor recover tank. It stores fumes from both the fuel tank and carb, then when you start the car again the carb will suck the fuel back into the carb. If it's leaking a lot then it probably is the carb float...while the engine is running have the hood open and air cleaner off and look down into the small venturies and see if fuel is pouring into it...the engine should be running really rough too.

You have a dangerous situation that has torched many cars and vettes are not immune...fuel leaks are nothing to take lightly. Take your time and do this one right. Watch out for fumes too while doing this cause it may make you light headed in a closed garage...open the garage and use a fan to get some circulation going...if it is still dripping fuel then put a container of water underneath to catch the drips and keep the fuel from evaporating. If you used some rags to wipe up the fuel then don't just throw them in the garbage...put some liquid laundry soap or liquid hand soap or liquid dish soap in a wash bucket with hot water and rinse the rag really good before puttin it in the garbage.

How did your hubby notice air getting around the carb gasket? Yeah, a rebuild would be in order, but to do it right you need some chemicals, like the carb dip tank, chemical gloves, carb cleaner to rinse, some ashphalt or concrete with drainage where there are no flowers or plants, patients, a work bench where you can keep the tiny parts from running away (I swear they sprout legs when you aren't looking).

Or, you can send the carb to Lars.

chicksmom

Thank you all for helping us. looks like we need to take it to the shop and get it rebuilt.

71redskin

sounds like you need a carb rebuild and without a doubt when it comes to qjets lars is the best...send it to him and he'll ship it back to you like new... welcome to the world of c3..."save the wave"

rihwoods

Did not you could ship a carb to him...any more info ??

chicksmom

do you know how much he charges? thanks.

72GACRZR

You can send Lars an e-mail, click on the past thread below, it's one he posted to and go down to his post, then you click on his name at the left over his avater and you will have the option to e-mail him. You do have to be logged in to do this.

http://forums.corvetteforum.com/show...231&forum_id=3



Good luck

The_Dude

I heard he was too busy with race season to do any work on carbs until the fall. It won't hurt to ask though.

stickboy

Last time I checked LARS didn't really work on the electronic carbs. They are fairly easy to rebuild if you take your time. Do a search for E4ME and you should come up with a list of parts and tools for working on them. Also the books by Doug Roe about rochester carbs has a great explanation of how these carbs work.

the website I had linked to in the past is broken. The tools are available at NAPA and aren't too expensive. I will see If I can find the part numbers when I get home.

tersian

It's definately an E4ME and Lars doesn't work on them, not because they are hard to rebuild, just because he has nothing to test them on. If someone wants to donate a 1981 vette to him, I am sure he'd rebuild a carb or two

In order to check the float height you have to drill the sucker and make your own tool for checking it. A major PITA. You NEED to get a GM service manual for that 1981 and follow the troubleshooting guide for the carb if you want to keep it original. If not, you'll need to do a search on replacing carb and dist. in a 1981.

87bob

The wife and I did Vettes on the Rockies with her 79. We had the same problem it was as simple as replacing the hoses going to the vapor canister they get old and then they crack. With a full tank the fuel expands and pushes up one of the lines and leaks out.